Return result from method

Conditionally returns a result depending on the input. This is in preparation for changing the MAX and MIN values of SignedAmount.
yancyribbens · Dec 11, 2024 · 8e4e6b1 · 8e4e6b1
1 parent f9daef6
commit 8e4e6b1
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Showing 3 changed files with 25 additions and 5 deletions.
diff --git a/units/src/amount/serde.rs b/units/src/amount/serde.rs
@@ -135,7 +135,9 @@ impl SerdeAmount for SignedAmount {
         i64::serialize(&self.to_sat(), s)
     }
     fn des_sat<'d, D: Deserializer<'d>>(d: D, _: private::Token) -> Result<Self, D::Error> {
-        Ok(SignedAmount::from_sat(i64::deserialize(d)?))
+        use serde::de::Error;
+        SignedAmount::from_sat(i64::deserialize(d)?)
+            .map_err(D::Error::custom)
     }
     #[cfg(feature = "alloc")]
     fn ser_btc<S: Serializer>(self, s: S, _: private::Token) -> Result<S::Ok, S::Error> {

diff --git a/units/src/amount/signed.rs b/units/src/amount/signed.rs
@@ -63,7 +63,20 @@ impl SignedAmount {
     pub const MAX: SignedAmount = SignedAmount(i64::MAX);
 
     /// Constructs a new [`SignedAmount`] with satoshi precision and the given number of satoshis.
-    pub const fn from_sat(satoshi: i64) -> SignedAmount { SignedAmount(satoshi) }
+    ///
+    /// # Errors
+    ///
+    /// On values exceeding [`SignedAmount::MAX`] or less than [`SignedAmount::MIN`]
+    #[allow(clippy::absurd_extreme_comparisons)]
+    pub const fn from_sat(satoshi: i64) -> Result<SignedAmount, OutOfRangeError> {
+        if satoshi < Self::MIN.0 {
+            Err(OutOfRangeError { is_signed: true, is_greater_than_max: false })
+        } else if satoshi > Self::MAX.0 {
+            Err(OutOfRangeError { is_signed: true, is_greater_than_max: true })
+        } else {
+            Ok(SignedAmount(satoshi))
+        }
+    }
 
     /// Constructs a new [`SignedAmount`] with satoshi precision and the given number of satoshis.
     ///
@@ -98,7 +111,7 @@ impl SignedAmount {
     /// per bitcoin overflows an `i64` type.
     pub fn from_int_btc(btc: i64) -> Result<SignedAmount, OutOfRangeError> {
         match btc.checked_mul(100_000_000) {
-            Some(amount) => Ok(SignedAmount::from_sat(amount)),
+            Some(amount) => SignedAmount::from_sat(amount),
             None => Err(OutOfRangeError { is_signed: true, is_greater_than_max: true }),
         }
     }
@@ -112,7 +125,12 @@ impl SignedAmount {
     /// per bitcoin overflows an `i64` type.
     pub const fn from_int_btc_const(btc: i64) -> SignedAmount {
         match btc.checked_mul(100_000_000) {
-            Some(amount) => SignedAmount::from_sat(amount),
+            Some(amount) => {
+                match SignedAmount::from_sat(amount) {
+                    Ok(sa) => sa,
+                    Err(_) => panic!("checked_mul overflow")
+                }
+            }
             None => panic!("checked_mul overflowed"),
         }
     }

diff --git a/units/src/amount/unsigned.rs b/units/src/amount/unsigned.rs
@@ -345,7 +345,7 @@ impl Amount {
         if self.to_sat() > SignedAmount::MAX.to_sat() as u64 {
             Err(OutOfRangeError::too_big(true))
         } else {
-            Ok(SignedAmount::from_sat(self.to_sat() as i64))
+            SignedAmount::from_sat(self.to_sat() as i64)
         }
     }